Poppet seat for air regulating devices

ABSTRACT

A poppet seat for air regulating devices, such as underwater diving equipment, includes a metal or plastic substrate around and through which synthetic or rubber seat material is molded. In its preferred form, this seat material surrounds the sides of the substrate and fills holes therein as well as an annular v-groove formed in the periphery of the substrate to further enhance the mechanical bond between the substrate and seat material.

CROSS-REFERENCE TO RELATED APPLICATIONS

If Any: None.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the art of poppet seats andmore particularly to poppet seats useful in air regulating devices. Inits most preferred embodiment, the present invention relates to animproved poppet seat in which synthetic or natural rubber seat materialis molded around and through an annular carrier. The invention alsorelates to a method for making a poppet seat of this type.

2. Description of the Prior Art

In the field of air regulating devices, such as those used in underwaterdiving equipment (more commonly known as scuba equipment) breathable airis provided to the diver from a pressurized air source, e.g. acompressed air cylinder, a surface supply hose, etc.

In most equipment a primary regulator is employed to reduce the airpressure available to the diver from the pressurized source, such as apressurized air tank, and a demand regulator functions to supply air inaccordance with the diver's breathing pattern. In current demandregulators, poppet seats have been commonly manufactured by providing acarrier base made out of plastic or metal material and having a grooveabout its center. Pliable seat material has been added to the groove andhas been held in place by friction and/or by adhesive bonding. In oneprior art device, such seats were exposed to pressures in the range of120-150 pounds/in² and made spring loaded contact with a coned orificemember to provide a complete seat of the pressure. Such poppet seats aresubjected to widely varying environmental conditions and cyclic usesince each time a breath is taken, a spring is relieved thereby allowingmovement of the coned orifice member toward and away from the seal andpermitting the bypass of breathable air to the scuba diver.

Such poppets have proved to be highly effective over extended periods oftime, but several design aspects of the current system make it possiblefor small leakage to occur. For example, the coned orifice can becomedamaged or the seating surface itself may be contaminated or deformed.These occurrences are especially likely in situations where theregulator is not maintained properly, e.g. if it is not reused asrecommended by most manufacturers. Leakage could also occur if the seatmaterial becomes delaminated from the substrate carrier base, as couldhappen for example if the adhesive or frictional forces became weakened.If any of these occurrences would take place while the diver was belowwater, normal emergency procedures, such as the use of a back-upregulator, would be employed to allow a divers safe return to thesurface. Repair of this regulator would then be required.

While the first two problems mentioned above may be readily cured byproper maintenance, the later problem is less easy to observe, as it canoccur over time. An improvement in design would be desirable to makesure the air supply is not bypassed due to inappropriate separation ofthe seat material from the carrier component.

SUMMARY OF THE INVENTION

The present invention features a seat for use in air regulating devices,such as second stage regulators in diving equipment, in which pliablematerial is applied through holes in the carrier to provide a mechanicalsecuring of the seat material to its substrate. In accordance withanother feature, the present invention employs such mechanicalattachment in combination with chemical bonding to increase, evenfurther, the adherence of the seat material to its substrate.

More specifically, the present invention features a technique forencapsulating a substrate base and anchoring seat material therethroughby means of through-hole molding using holes which are geometricallyreversed when compared to the direction from which delamination forceswould be most likely to occur.

Yet another feature of the present invention is to provide anencapsulated substrate, wherein the encapsulating seat material forms aseating member that also flows into a v-groove surrounding the peripheryof the substrate to enhance attachment thereto. In still anothermodification of the later feature, the v-groove intersects a pluralityof through holes to further enhance the security of the seat andsubstrate.

The invention also features a method for manufacturing a valve seat ofthe type including an annular base and an elastomeric seating materialaffixed to the base. The method includes the steps of forming an annulargroove in the base and securing the seating material to the base suchthat the seating material contacts at least a portion of the groovegenerally in opposing relation with respect to an upper surface of thebase.

How these and other features of the present invention are accomplishedwill be described in the following detailed description of the preferredembodiment, taken in conjunction with the drawings. Generally, however,they are accomplished by using a synthetic or natural rubber seatmaterial and molding it with a substrate which is preferably of annularform. In the most preferred embodiment, the substrate includes av-groove around its periphery and a plurality of holes so that themolding material passes through the holes and around the v-groove, mostpreferably encapsulating the entire periphery of the carrier. In themost preferred embodiment, the holes of the substrate are geometricallyreversed to increase the seats ability to withstand any delaminationforces. Other ways in which the objects of the invention areaccomplished will become apparent from the following detaileddescription after it is read and understood by those knowledgeable inthe art. Such other ways are also deemed to fall within the scope of thepresent invention.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a bottom plan view of the poppet seat forming the mostpreferred embodiment of the present invention;

FIG. 2 is a side elevation showing the seat material lip extending fromthe upper surface of the seat; and

FIG. 3 is a cross section taken along the line 3—3 of FIG. 1 showing thelocation of the molding material and the reversed drilled holes andv-groove around the perimeter of the substrate.

In the various FIGURES like reference numerals are used to indicatedlike components.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Before proceeding to the detailed description of the preferredembodiment, several general comments should be made about theapplicability and the scope of the present invention. First, with regardto the materials to be employed, the carrier or substrate material ismost commonly prepared from a metal such as brass or stainless steel,although plastics could also be employed. As to the seat materialitself, synthetic or natural rubber materials are preferred, the mosttypical being silicone rubber which has been used heretofore inpreparing such seats for air control devices. A preferred seat materialin the present invention is silicon rubber, such as Silastic LCS 755silicon rubber, manufactured by Dow Corning.

As to the use of the seat described in this section of thespecification, it could be employed in a number of devices other thanthat mentioned in the background section hereof. For example, thearticle shown in the drawings could be used in a wide variety of air orother fluid control devices wherein it is desired to have structuralrigidity and mechanical adherence of a pliable seat material to asubstrate. This should be kept in mind as the balance of thespecification is read, even though demand regulator poppet seats arementioned and shown. One familiar with air control devices could readilyadapt the teachings of the present invention to other seat design,taking into account such factors as diameter, thickness, applicabledurometer, environmental conditions and the like. Furthermore, one couldrefer to the instruction manuals, engineering bulletins and maintenanceguides for such regulators as the Scubapro Models D400, D350, D300 andAIRI to learn more about such poppet seats and their interaction withother control device components. Copies of Scubapro Engineering BulletinNos. 237 and 238 are submitted with this specification for that purpose.

Proceeding next to a brief description of the prior art, prior artmolded seats have been made using annular brass inserts or substrates,much like a washer, having a central through opening and an annulargroove in one surface thereof. Rubber was added by a molding process tothe groove to provide a seat for the coned orifice mentioned above.

In the present invention, molded rubber in a groove is replaced byrubber which is molded with the insert so that it, in the most preferredembodiment, surrounds the sides and fills various through holes to bedescribed in detail hereafter. A molded seat 10 according to the presentinvention is show in bottom view in FIG. 1. The molding material 11encases the periphery 12 of a substrate 14, and the rubber passesthrough holes 17-20 as shown at 22-25. The central opening of thesubstrate is shown at 27.

A side view of the molded seat is shown in FIG. 2 when a lip 30 is shownextending from the upper surface 32. The configuration of the lip willbecome more apparent as the explanation continues with a description ofFIG. 3.

FIG. 3 is a sectional view showing that the substrate in the mostpreferred embodiment, includes a v-groove 33 surrounding its periphery,while a recess 35 extends around its upper surface. FIG. 3 alsoillustrates that through holes 17-20 are provided, as shown particularlyat the bottom of this FIGURE. For hole 19, reverse drilling has occurredso that the hole has a smallest diameter 36 near its upper surface 32and a larger diameter portion 38 near the bottom surface.

From this description and from FIG. 3 it is evident that the holes 17-20intersect the bottom of the v-grooves 33 so that rubber may flow fromthe holes 17-20 into the v-groove 33 or vice versa. Note that while therubber does not extend beyond the bottom surface 40 of the brasssubstrate 14, it does flow into portion 38 of the holes 17-20 to resistany delamination forces which may exist.

In addition to the mechanical forces used to hold the molded seatmaterial to the substrate, chemical bonding aids may also be employed.In the most preferred embodiment of the invention, chemical bonding isprovided by using a bonding agent, and preferably methanol based agents,such as Chemlock Adhesive No. Y1540, available from Lord ChemicalProducts.

While the preferred embodiment shows two different techniques forincreasing the mechanical bonding of the seat material to the insert,each of the techniques, the through holes 17-20 and the v-groove 33,could be employed separately to enhance performance when compared to theprior art devices described above. Optimum results would be obtained byusing both, together with a chemical bonding agent.

While the present invention has been described and illustrated inconnection with a single preferred embodiment, it is not to be limitedthereby but is to be limited solely by the claims which follow.

What is claimed is:
 1. A method for manufacturing a valve seat of thetype including an annular base having an outer annular periphery, acentral aperture extending from an upper surface to a lower surface andan elastomeric seating material affixed to the base, the methodcomprising the steps of: forming at least one aperture in the baseextending from the upper surface adjacent to the central aperture;forming an annular groove in the base, the annular groove extending intocommunication with the at least one aperture, at least a portion of thegroove being in generally opposing relation with respect to the uppersurface; and securing the seating material to the base by molding theseating material onto the base such that the seating material at leastpartially contacts the upper surface and the outer annular periphery,flows through the at least one aperture, and contacts the portion of thegroove.
 2. The method of claim 1, wherein the annular groove has agenerally V-shaped cross section and is formed in the periphery of thebase.
 3. The method of claim 1, wherein the securing step includeschemically bonding the seating material to the base.
 4. A valve seatcomprising: a base having an annular body, an upper surface, an outerperiphery, a central opening and at least one retaining surface spacedfrom the upper surface and at least partially opposed to the uppersurface, an aperture extending from the upper surface through the bodyadjacent to the central opening to the outer periphery; and a seatmaterial affixed to the base, extending from the upper surface throughthe aperture and contacting the retaining surface, the seat material atleast partially enveloping the upper surface and the outer periphery,whereby the seat material bears against the retaining surface to resistforces tending to remove the seat material from the base.
 5. The seat ofclaim 4, wherein the base is an annular metallic ring and the seatmaterial is a moldable elastomeric material.
 6. The seat of claim 4,wherein the base is made of a plastic material.
 7. The seat of claim 4,wherein the base includes an annular groove, at least a portion of theannular groove being oriented in opposing relation with respect to theupper surface to define the retaining surface.
 8. The seat of claim 7,wherein the annular groove has a V-shaped cross section and is formed inthe periphery of the base.
 9. The seat of claim 4, wherein the seatingmaterial is chemically bonded to the base.
 10. A seat assembly for usein an air regulating device, the seat assembly comprising: an annularsubstrate having an upper surface, an outer periphery, a centralaperture, a plurality of apertures extending from the upper surface andthrough the substrate adjacent to the central aperture, and a retainingsurface at least partially opposed to the upper surface, the retainingsurface being at least partially formed by an annular groove formed inthe outer periphery of the substrate, the groove communicating with theapertures; and a seating member extending around at least a portion ofthe upper surface, at least a portion of the outer periphery and atleast a portion of the retaining surface, the seating member alsoextending into the apertures and thereby into the annular groove,thereby at least partially encapsulating the substrate and bearingagainst at least a portion of the retaining surface to anchor theseating member on the base.
 11. The seat assembly of claim 10, whereinthe substrate further includes a lower surface generally opposed to theupper surface and the plurality of apertures surround the centralaperture and extend from the upper surface to the lower surface.
 12. Theseat assembly of claim 11, wherein the plurality of apertures aregeometrically reversed with respect to the upper surface to define aportion of the retaining surface.
 13. A valve seat comprising: a basehaving an annular body with an outer periphery, a retaining surfaceopposite an upper surface of the outer periphery, and an outercircumferential perimeter extending between the upper surface and theretaining surface, a central opening extending from the upper surface,and an aperture extending from the upper surface through the bodyadjacent to the central opening to the outer periphery and incommunication with the retaining surface; and a seat material affixed tothe base, the seat material continuously extending along the uppersurface through the aperture along the retaining surface and along theperimeter, the seat material at least partially enveloping the uppersurface, the retaining surface and the outer circumferential perimeter,whereby the seat material resists forces tending to remove the seatmaterial from the base.
 14. The seat of claim 13, wherein the bodyincludes a bottom surface opposite the upper surface and wherein theretaining surface extends intermediate the upper surface and the bottomsurface.
 15. The valve seat of claim 13 wherein the central openingprovides an air passage through the base.
 16. A valve seat comprising: abase having an annular body with an outer periphery, a lower surfaceopposite an upper surface of the outer periphery, an outercircumferential perimeter extending between the upper surface and thelower surface, a central opening extending from the upper surface, andan aperture extending from the upper surface through the body adjacentto the central opening to the lower surface to the outer periphery; anda seat material affixed to the base, the seat material continuouslyextending along the upper surface through the aperture, along the lowersurface and along the perimeter, the seat material at least partiallyenveloping the upper surface, the lower surface and the outer perimeter,whereby the seat material resists forces tending to remove the seatmaterial from the base.
 17. The seat of claim 16, wherein the bodyincludes a bottom surface opposite the upper surface and wherein thelower surface extends intermediate the upper surface and the bottomsurface.
 18. The valve seat of claim 16 wherein the central openingprovides an air passage to the base.
 19. A valve seat comprising: a basehaving an annular body with a central opening extending from an upperside of the body and an outer side, the body including at least oneaperture extending therethrough from the upper side adjacent to thecentral opening and a wall between the outer side and the aperture; anda seat material encapsulating the wall on at least four sides, wherebythe seat material resists forces tending to remove the seat materialfrom the base.
 20. The valve seat of claim 19 wherein the centralopening provides an air passage to the base.
 21. A valve seatcomprising: a base having an annular body with an upper surface, anouter circumferential side and a central opening extending from theupper surface along a first axis, the body including an apertureextending along a second axis from the upper surface through the bodyadjacent to the central opening, an outer wall portion bounded by theaperture, the outer side, a first surface non-parallel to the apertureand the outer side, and a second surface spaced from the first surfaceand oblique to the aperture and the outer side; and a seating materialcontinuously extending into the aperture, along the outer side and alongthe first and second surfaces to encapsulate the wall portion, wherebythe seat material resists forces tending to remove the seat materialfrom the base.
 22. The valve seat of claim 21 wherein the centralopening provides an air passage to the base.
 23. The valve seat of claim4 wherein the central opening provides an air passage through the base.